1. Field of the Invention
The present invention relates to a method for preventing the adhesion of impurities such as scale on the sealing mechanism of a high pressure steamer in continuous scouring of a long cloth.
2. Description of the Related Art
In the pretreatment of a woven or knitted cloth produced industrially, the cloth is generally subjected to scouring and bleaching with the use of wet heat in succession to singeing and desizing. As a means for scouring and bleaching of a long cloth, it has been proved that continuous pretreatment by using a high pressure steamer developed by the present applicant is most effective. In such a high pressure steamer, a sealing mechanism, which is to allow the taking in and out of a cloth continuously therethrough by preventing the leakage of pressure inside of the steamer body, must be provided at the inlet and the outlet of the cloth so as to maintain the interior of the steamer body at high pressure. Said sealing mechanism comprises a pair of seal rubber rolls pressed with each other, and the cloth to be treated is passed between said pair of seal rolls.
In carrying out the scouring treatment of a long cloth continuously by using such a high pressure steamer, it is usual that the cloth is soaked with a prescribed scouring agent solution outside of the steamer body, and then the cloth thus soaked with the scouring agent solution is supplied through the sealing mechanism into the steamer body for wet heat treatment. When there exist such impurities as waste yarns, waste size and fluffs on the surface of the cloth to be supplied into the steamer, these impurities are transferred and adhered on the surface of the seal rolls. Since such compounds as calcium bicarbonate and magnesium bicarbonate are contained together with the scouring agent in the scouring agent solution, these impurities are accumulated, pressed and solidified on the surface of seal rolls, and the thus solidified product is hardened likely as stones due to the effect of high temperature treating solution in the steamer body as well as the degeneration of the treating agent. Accordingly, the surface of the seal rolls is injured, and the sealability by using seal rubber rolls is unavoidably deteriorated.
To eliminate such a drawback, various means have been proposed for removing impurities adhered on the surface of seal rolls, but an effective and practically applicable method has not yet been developed.